Electrical distribution system



Nov. 17, 1936. H. J. FRANK ET AL 2,061,515

ELECTRICAL DISTRIBUTION SYSTEM Filed Feb. 25, 1955 4 Shee'ts-Sheet 1 w m Z W M u wwww m mz. w A ad 5 5 5 L L .flg/ I W JM w m Nov. 17, 1936. H. J. L. FRANK ET AL 2,061,515

ELECTRICAL DISTRIBUTION SYSTEM Filed Feb. 25, 1955 4 Sheets-Sheet 2 JIWm 40% Nov. 17, 1936.

-H. J. L. FRANK ET AL ELECTRICAL DISTRIBUTION SYSTEM Filed Feb. 25, 1935 4 Sheet-Sheet s Nov. 17, 1936. H. J. L. FRANK ET AL ELECTRICAL DISTRIBUTION SYSTEM 4 Sheets-Sheet 4 Filed Feb. 23, 1935 INVENTORJ.

wan; .1 d hum 1W 2 ATTORNEY.

Patented Nov. 17, 1936 UNITED STATES PATENT OFFICE ELECTRICAL DISTRIBUTION SYSTEM Harrison 3. L. Frank, William A. Harper, and

Joseph A. Messing. Detroit, Mich.

Application February 23, 1935, Serial No. 73W

6 Claims. (Cl. 247-3) closed a system of the character under consideration employing as the current collector for insertion into the trolley duct, a depending portion which rides outside the duct and througha slot thereof and which supports a conductor leading from contacts in the head or blade to an. external load and which is provided with a handle for manipulation, a cross bar rotatably and resiliently mounted on the depending portion and provided with rollers for riding against partsv of the slotted wall of the duct. The cross bar is resiliently mounted on the depending portion of the trolley for the purposes of providing a resilient resistance which absorbs the thrust that accompanies the action of inserting the blade, preventing the action of blade insertion from being carried on so freely as to permit the blade to be inserted too far into the duct and against the wall of the duct opposite the slotted wall, with consequent injury to the blade parts, and providing a, bearing for the trolley during blade insertion and removal that facilitates these acts, and of drawing the blade down towards the slotted wall of the duct to cause its contactsto engage the bus bars as firmly as possible, the spring of the resilient mounting insuring adequate contact pressure.

The trolley of this application is in general like the trolley of the earlier application above described. A principal difference between the trolley of this application and the trolley of the earlier application, however, exists in the details of construction of the blade and the cross bar parts, and these details will be specifically described in a later part of this specification.

One important detail that may be mentioned here is the feature that the trolley blade is provided with U-shaped contacts which receive free edges of the bus bars along which the blade rides. In previously known trolleys the engagement of a trolley contact and a bus bar is such that spring means must be relied upon to insure adequate contact pressure between the trolley contacts and the bus bars, as the trolley shifts vertically with respect to the duct. In the construction here shown, due to the fact that the trolley contacts are U-shaped and receive the edges of bus bars, the contacts wipe along opposite vertical sides of the bus bars, and this insures adequate contact pressure regardless of whatever relative shifting of the trolleys with respect to the bus bars takes place.

The details of construction of the system here shown may well be understood upon reference to the following detailed descriptive matter re- 5 lating to the appended drawings. Referring to these drawings, it will be seen that,

Fig. 1 shows a trolley of the invention in end view and in a bus duct and in on position; FiFigl. 2 is a cutaway view as it looking down on Figs. 3 and 4 are views like Figs. 1 and 2 but showing the trolley with its parts in the position they have when the trolley is being inserted;

Fig. 5 is a sectional view of the trolley blade;

Fig. 5a is a composite view showing trolley blade parts;

Fig. 6 is a sectional view of a double fuse trolley blade modification;

Fig. '7 is a view as if from the left of Fig. 6;

Fig. 8 is an end view of the blade of Fig. 6;

Fig. 9 is an enlarged fragmentary sectional view of'a modified detail;

Figs. 10 and 11 are fragmentary views showing 7 how the bus bars may be clamped in place; 5

Figs. 12' and 13 show contact modifications in detail.

Before undertaking a detail description of the parts of the trolley and duct here shown, it will be pointed out that a trolley duct is in the nature 30 of a sheet metal duct of rectangular cross section and having a wall provided with an elongated slot through which may be inserted the blade part of the trolley and in which rides the part of the trolley that depends from the blade, and in which also rides the cross bar of the trolley. On opposite sides of the slot there are positioned bus bars and these form tracks along which ride trolley contacts. In commercial in stallations the duct is so positioned that the slotted wall of the duct is horizontally disposed to form the bottom wall and therefore the trolley may be seen to hang down or depend from the duct with its blade within the duct, and with its depending portion riding within the duct slot along the duct. For purposes of convenience of illustration, the duct shown in the appended drawings is shown with its slotted wall vertically disposed rather than horizontally disposed. This expedient has been adopted only forpurposes of illustration and it will be considered that in commercial installations the practice is followed of having the slotted wall form the bottom of the duct.

In the construction shown, the duct comprises 55 bottom wall whose portions l4 are separated by a slot I! defined by the flanged edges ll of the pertions l4. The duct, or at least the portion thereof next adjacent the slotted wall, is lined with insulation I1 and the portions l4 of the slotted wall mount bus bars 18-49 of angular cross section, these having free edges 23 adapted to be received within U-shaped contacts of the trolley. The bus bars may be held in the duct by spaced beads or tongues 2| cut in from the duct, crimping the insulation and the bus bars correspondingly.

The trolley shown in this application comprises a blade or head 33 whose width is almost equal to the distance between walls ll of the duct and whose thickness is less than the width of the slot l5, the proportions being such that the blade may be inserted into the duct through the slot thereof (Fig. 3) and then rotated ninety degrees so as to traverse the duct (Fig. 1). The lower portion of the trolley blade 30 is provided with an axle or pin 3| which connects the blade to the ears 3 la on the forked end of a tube 32 which forms the depending portion of the trolley, and the lower end of this tube is formed as a handle 33 by means of which the trolley may be manipulated for trolley insertion or. removal or for trolley movement along the duct. The pivot at 3| permits free movement of the handle with respect to the head and eliminates binding of the head in the duct as the trolley ispulled by its handle.

At the lower edge 34 of the blade there are provided through-slots leading from one face of the blade to the other and in these through slots are provided U-shaped contacts 35 which receive the free edges 20 of the bus bars I8-l9, the contacts being formed frictionless by being provided with rollers or balls 35 seated in plates 31 secured in the blade 30, the balls passing through holes 33 of the U-shaped contacts 35. In the blade are binding means 39 for the terminals 40 of conductors 4| which lead to the external load, these conductors extending from the blade through the tube 32 connected to the blade and out through a hole 42 in the side of the tube, the conductors being doubled back upon themselves so as to pass through a cable clamp 43 secured to the sides 44 of a U-shaped strap 45 through whose bight 45 passes the tube 32. The characteristics and functions of this strap will be described at a later stage of this specification. One or both of the lines from contacts 35 to conductors 4| may be fused through one or more fuses F.

The contacts 35 may be provided with rollers or balls 35 not only on the vertical surfaces, as shown, but also on the horizontal or bight surfaces, for frictionless engagement with the edges of the bus bars, as shown in Fig. 12; and if desired, the contacts may be in the form of flanged wheels 35aa, substantially as shown in Fig. 13.

Fig. 5 shows a construction wherein but one line from a contact 35 to a conductor 4| is fused, and Fig. 6 shows a construction wherein the two lines from contacts 35 to conductors 4| are fused. Inasmuch as the specific details of construction of the electrical connections within the blade, by means of which such fusing is accomplished, are of no great importance in this application, they will not now be described, it being sufficient to say that the construction is such that the fuses are replaceable and renewable.

The U-shaped strap 45 previously mentioned as supporting the cable clamp 43 terminates in ears 41 extending from the sides 44, and these ears are connected by a bridging strap 43 permanently secured thereto and having an aperture through which passes the tube 32 leading to the trolley blade.

'Ihe U-shaped strap 45 and the bridging strap 43 comprise the cross bar of the trolley, and it will-be observed that the length of the cross bar is considerably greater than the width of the blade, for reasons that will become apparent.

Pins 43 in the ears 41 journal rollers 50 having flanges 5|, these rollersbeing of a diameter substantially equal to the distance between the flanges I. at the slot l5 of the duct, with the flanges 5| of the rollers being of greater diameter whereby the rollers can ride within the duct slot against the flanges IS with the roller flanges 5| engaging the portions l4 of the duct to prevent complete insertion of the rollers 50 within the duct and to prevent the cross bar from being inserted into the duct..

The rollers 50 may be of the form shown, or

of the form shown at 44, in application Serial No.

727,516, or may be compounded to eliminate thrust without friction in all directions, as shown at |2|4, in application Serial No. 727,516.

Surrounding the tube 32 and within the strap 44 is a coiled compression spring 52, one of whose ends abuts the bridging strap 48 and the other of whose ends abuts an abutment ring 52a surrounding the tube 32 and anchored thereon by means of a cross pin 53 passing through the tube 32. The spring tends to separate the parts 52a--53 from the bridging strap 48, and since the parts 52a53 are immovable with respect to the tube 32, and since the tube 32 is fixed to the blade 30, the spring 52 tends to pull the blade down towards the bridging strap.

In Fig. 9 there is shown a detail of construction intended as an alternative to the contact construction of Figs. 5 and 6. It will be remembered that in Figs. 5 and 6 the contact 35 was shown as provided with a ball 36 for providing frictionless engagement between the contact and Operation and features The operation and features of the trolley here shown will now be reviewed.

When a, trolley is to be inserted into the duct, the operator grasps the trolley at the handle 33 and, first making sure that the blade is aligned with the cross bar, as in Figs. 3 and 4, he inserts the blade into the duct through the slot l5 thereof until the flanges. 5| of the rollers engage the portions l4 of the duct. Further pressure upwardly on the handle causes the tube 32 and the blade 30 to move with respect to the cross bar against the resistance of the spring 52 and the operator continues pressing upwardly on the handle 33 until the lower edge 34 of the blade clears the free edges 20 of the bus bars |8|9. when this happens he gives the handle 33 a turn of ninety degrees so that the blade will traverse the duct as in Figs. 1 and 2. Then he releases his upward pressure and permits the spring 52 to pull the blade down so that its contacts 35 will receive the free edges 20 of the bus bars.

When a trolley is to be removed form a duct, the operator presses upwardly on handle 33 against the resistance of the spring 52 to raise the blade within the duct so that its lower edge 34 clears the free edges 20 of the bus bars, whereupon he gives a quarter turn to the blade so as to cause it to assume the position of Figs. 3 and 4, after which gravity or a pull on the handle 33 downwardly will cause the trolley to leave the duct with the blade passing from the duct through the slot IS in the bottom wall.

It will be observed that in the action of insertion of the trolley the spring 52 provides a resilient resistance which absorbs the thrust th'ataccompanies the action of inserting the blade, and thus prevents the blade from being jammed into the duct against the top wall ll thereof with consequent injury to the blade parts. Furthermore, the cross bar and'spring construction provides a bearing forthe trolley as a whole, journalling the tube 32 particularly, and this facilitates the ac tion of blade insertion and removal, relieving the 'operator from the necessity of exercising as great care during these acts as would be required were v the cross bar and spring construction omitted. The cross bar and spring construction automatically aligns the trolley parts with respect to the duct and maintains the parts in proper alignment during the acts of trolley insertion and removal. Furthermore, the spring 52 acting on the cross bar functions to draw the blade down towards the slotted wall of the duct and cause its contacts to engage the bus bar with adequate contact pressure, and functions to clamp the trolley to the duct by virtue of the fact that it clamps the rollers on opposite sides of the slotted wall, namely the cross bar rollers 5|] with their flanges 5i and the contacts 35 with their balls 36, so that the movement of the trolley along the duct is not accompanie ,by excessive vertical movement and shiftingbf t e trolley with respect to the duct. In the event that such vertical shifting does take place, as would be the case were the trolley to pass over a bump in the duct parts, the contacts 35 do not lose their engagement with the bus bars, inasmuch as the balls 36 thereof ride against vertical faces of the bus bars and merely ride up and down on these vertical faces as they ride along the duct, when vertical shifting in the trolley does take place.

It will also be observed that the use of the contacts shown and the use of the pivot at M insures no loss of contact regardless of how the handle 33 is moved with respect to the duct, or how the head 30 tilts across the duct; therefore, the same result is obtained in this way as would be obtained if a universal joint were used in the tube 32.

Polarization Inasmuch as it is considered desirable to so construct a trolley and duct system that a trolley may be inserted into a duct in one way and one way only, whereby polarization or proper orientation of trolley contacts with respect to duct bus bars is assured, means are provided in the construction here shown whereby such polarization may be efiected.

Referring to the drawings, it will be observed that the bus bars l8 and I9 are so constructed that the free edge 20 of the bus bar it is considerably below the level of the free edge 2d of the bus bar it. Correspondingly, the blade and its contacts 35 are so dimensioned that one of the contacts is displaced with respect to the other so that its bight is considerably above the bight of the other. Consequently, when a trolley is inserted into a duct and when the quarter turn that completes the act of insertion is given to the trolley, both contacts 35 will engage both bus bars onLv in the event that the proper ones of the contacts 35 are in engagement with the prop-.

er ones of the bus bars. If improper pairing-01f of blade contacts and bus bars has taken place, the circuit to the branch load through conductors M will not be closed, inasmuch as one contact will not be in engagement with one of the bus bars. When the operator observes that the circuit is not closed, he lifts the blade from the bus bars and turns the blade in the opposite direction, whereupon proper pairing-oil and proper polarization will take place, as will be evidenced by the fact that the circuits through conductors 4| will be closed.

Now having described the electrical distribution system shown in the appended drawings, reference will be had to the claims which follow for a determination 'of the monopoly of this application.

We 'claim:

1. An electrical distribution system comprising a trolley duct having a horizontal wall provided with a narrow elongated continuous slot and and a current collecting trolley having-a head wide enough to straddle the rails, the lower horizontal edge of the head having slots containing rollers and receiving the upwardly projecting edges of the rails, the slots containing contacts embracing and making electrical contact with the rails.

3. An electrical distribution system comprising a trolley duct having a horizontal wall provided with a narrow elongated continuous slot and containing bus bar rails presenting exposed surfaces transverse to the slotted wall, and at current collecting trolley having a head having the surface thereof adjacent the slotted wall provided with slots receiving the bus bar rails whereby the head is guided thereby as it rides along the duct.

4. An electrical distribution system comprising a trolley duct having a horizontal wall provided with a narrow elongated continuous slot and containing bus bar rails presenting exposed surfaces transverse to the slotted wall, and a current collecting trolley having a head having the surface thereof adjacent the slotted wall provided with slots receiving the bus bar rails whereby the head surfaces transverse to the slotted wall, and a current collecting trolley having a head having the surface thereof adjacent the slotted wall provided with slots receiving the bus bar rails thereby the head is guided thereby as it rides along the duct, and containing contacts provided with rollers engaging the exposed surfaces of the bus bars and restraining movement of the head transversely of these exposed surfaces.

6. In combination; a trolley duct having a wall provided with a continuous elongated riding slot, and having its edges at the slot flanged transversely of the wall into the duct, and a bus bar rail in the duct lying adjacent a flanged edge and having the surfaces thereof transverse of the wall exposed, a current collector trolley head having a slot in the surface thereof parallel to the wall receiving the bus bar rail so as to be guided thereby as it rides along the duct. 

